precision mediump flaot;
float sdCircle(vec2 p, float r) {
    return length(p) - r;
}


float sdBox(vec2 p, vec2 b) {
    vec2 d = abs(p) - b;
    return length(max(d,0.))+min(max(d.x,d.y),0.);
}

void mainImage(out vec4 fragColor,in vec2 fragCoord){
    vec2 uv=fragCoord/iResolution.xy;

    uv = (uv - .5) * 2.;

    uv.x *= iResolution.x/iResolution.y;

    float d = sdBox(uv, vec2(.6,.3));
    fragColor = vec4(vec3(c),1.0); 
}
